Pit raiser



Feb. 20, 1951 D. E. MULHLLAND PIT RAISER 4 Sheets-Sheet l Filed Dec. 3o.' 1947 f INVENToR. Dan/id EMuzzLolzgnd,

' HIS TORNEX Feb. 20, 1951 D. E. MULHOLLAND PIT RAISER '4 sheets-.sheet 2 Filed Dec. 50. 1947 INVENTOR. D/JHLMz/zlfzallzzd,

HS'ATTO RNE'Y Feb. 20, 1951 D. E. MULHOLLAND PIT RAISER 4 Sheets-Sheet 3 Filed Dec. 30, 1947 INVENTOR. Dil (ZEMuIIwILznd,

HIS ATTORNEY Feb. 20, 1951 D E MULHOLLAND 2,542,557 I PIT RAISER Filed Dec. 30, 1947 4 Sheets-Sheet 4 52 ,58 VJ 55 .59' 54 56 a i 6\ 71 74 Q E 5 Z 2l Z5 l9 HIS TTURNEK Patented Feb. 20, 1951 UNITED STATES i yPATENT DFFICE PIT BAISER David E. Mulholland, Reading, Pa. Application December 30, 1947, Serial No. 794,581 9 claims. (o1. 153 48) 1 This invention pertains to a machine for and method of removing pits in a surface of metal sheets.

In the course of manufacture of stainless steel sheets, voids are at times developed in, at or adjacent to a surface of a sheet and Subsequent polishing operations disclose the presence of such voids, commonly rmed pits. Unless these pits are successfully removed the sheets are not acceptable to the trade or are not commercially saleable.

The principal object of the present invention is to provide an improved machine for and method of removing pits from the polished surfaces of metal sheets.

`Another object ofthe invention is theprovision of an improved means whereby pits in the surface of a metal sheet may be positively and definitely spotted preparatory to removing them.

A further object of the invention is the provision of a light mechanism or arrangement whereby pits in a surface of a metal sheet may be accurately aligned with a yieldable means operating on the other side of the sheet.

The above and numerous other objects will become apparent from the succeeding description considered together with the accompanying drawings wherein; Y

Figure l is a side elevational view of a machine for raising pits in surfaces of steel sheets.

Figure 2 is a horizontal sectional view taken along the lines 2 2 of Figure 1, looking in the direction of the arrows.

Figure 3 is a side elevational View taken along the lines 3 3 of Figure 2, looking in the direction of the arrows.

Figure 4 is a vertical sectional View taken along the lines 4 4 of Figure 2, looking in the direction of the arrows.

Figure 5 is an end elevational View taken along the lines 5 5 of Figure 1, looking in the direction of the arrows. y f

Figure 6 is a, sectional view taken along the lines 6 6 of Figure 5, looking in the direction of the arrows. Referring now in detail to the drawings, wherein like reference characters indicate like parts, the numeral l is employed to designate, in

a somewhat general manner, an exemplied form of a machine for removing pits and the like from a metal sheet. The machine generally comprises a U-shaped casting or frame 2 disposed on its side and having an upper jaw 3 and a lower jaw 4 spaced a predetermined distance 2 from one another in a vertical direction. The bottom jaw may 'be formed with suitable pads 5 arranged to rest upon and be secured to any desirable foundation 6 to retain the frame in a fixed, steady position.

Forming an integral part of the forward or free end of the lower jaw is a lower cylinder l having disposed therein a lower ram 8 arranged for vertical movement with the related cylinder. The lower ram has a shouldered portion 9 opposed from a shouldered ledge v|53 formed in the cylinder and againstv which a coil spring Il or any other type of resilient means may bear. The coil spring extends around a necked part l2 of the lower ram and is precompressed so that when the lower ram has completed its upward movement as will be discussed again in detail hereinafter, the coil spring will return the ram to its lower or starting position. Closing off the lower extremity of the cylinder I is a diaphragm i3 which is made of an oil resisting rubber stock and is clamped in place by a lower diaphragm cover plate I4. This cover plate is anchored to the. cylinder and has axially thereof an inlet l5 to whichthere is attached a coupling lleading from a hydraulic system i1 of the machine. Accordingly, under certain operating conditions fluid pressure will be admitted to the lower area ofthe lcylinder against the diaphragm to thus urge the lower ram upwardly and when the fluid pressure is relieved the coil spring will urge the lower ram downwardly.

Suitably anchored to the upper end of the lower cylinder is an anvil plate support I8 which has mounted thereon a bottom retainer ring i9. Disposed within vthe retainer ring is an anvil 2B, stepped as at 2| with respect to the retainer ring and stepped as at.22 with respect to the anvil support plate to thussassure a iirm interlock between these components. A piston 23 formedof yieldable or elastic or compressible material is iirmly secured to the upper end of the lower ram through the medium of a piston holder 24 the latter of Awhich is threadedly or removably associated with the ram to be made a part thereof. The anvil 20 is fixed as recited above and thus affords@J support for the sheet of metal `(not shown) to be worked upon. The center of the anvil is provided with a chamber 4into which an extrusion 25 of the pistonextends. y

While the lbody portion of the piston may be conveniently made in the form of a cone the extension is desirably of cylindrical form with -its diameter of about 0002 inch less than the diameter of the chamber.` This relationship ofextension and chamber prevents the yieldable material of the piston from being extruded and yet provides the necessary clearance thereabout to enable the piston to move slightly with respect to the anvil. The piston is of course removably secured in place as previously recited for the purpose of inspection and further to replace the piston if and when it becomes Worn beyond a certain permissible degree.

Thus it will .be now noted that .asheet `of metal containing a pit or pits may be disposed vbetween the jaws of the frame to be: supported upon or by the anvil with the pit appearing in the sur face of the sheet opposed to the surface thereof.

in contact with the anvil. A positioning of the pit in vertical alignment with thefpiston.` extension or anvil chamberwillproperly posif. tion the sheet of metal so that an upward movement of the lower ram will cause the piston-.exe tension to bear against the underside of the sheet andraise the'ipit for thecompleteremoval thereof from the sheet.

The upper jaw Yof theframecarriesan vupper cylinder 26 forming an. integral part thereof, and containing therein an upper. or holding.. ram 21. The upper extremity of-the. upper cylinder is covered bya flexible or yieldable diaphragm 2B which is clamped in placeby anV upper diaphragm cover 29, the latter of. which, as .will be understood, isy removably secured .to the cylinder by means of holding bolts 30 or the like. The primary purpose oi' the diaphragms inthe .upper and lower cylinders is Yto eliminate. the..use..of packingY aroundv the. rams` past whichleakage of the fluidunder. pressuremight. .occur .due .to the exceedingly short stroke .oi each ram and the high pressure involved., Such. leakage if permitted to. occur would be. objectionable and undesirable for purposeswhich are obvious- The upper diaphragm cover has` a. central portto which a .coupling 3l Yis .attachedior the introduction. of uid 'pressureto thefexposed surface of the diaphragm for'urgingiheupper ranr downwardly from ,its illustrated.. position. The `upper `ram andcylinderare shouldered as at 32 presenting rests against which. acoilLspring 33 may bear. The coil spring, extending 4around the upper ramV within the .related cylinder. is arranged to return the upper ram toits uppermost position upon areleasefof thafiuid pressure from against the upper diaphragm...

Outstanding from the upper jawat a location below .therupper cylinder is-.a housing 34fformed lay-transversely spaced. angle-shaped. legs 35. Removably secured toeach leg isa Wedge-.shaped guide plate 36 adjustably mounted -on the. leg so as to dene a delinite and iixedor adjustable area therebetween.. Arranged tov move. vertif. cally-within the leg-guideplate dened areais afram extensionv 31 `having an upper horizontal wall 38 apertured for the .relatively neat acr:om-.v modation of av shaft 39. projecting downwardly from the upperram. Lockingmeans Mllisassoe ciated with.the shaft to securecr'mlythe. ram extension to the. upper ram so..that .any .vertical movement .oi the ra1n..willv be reflected; mits extension.

The lower 'extremity ofthe. ram extensionhas, formingV a part thereof longitudinally extending arms 4I spacedY .transversely of the. frame and arranged -to carry guide. bars 42. A slide plate 43 Vis arranged with recesses vor outwardly iacing grooves i4 for the-accommodation of Vthe guide bars and'thisiarra-ngement permits Ya 'longie tudinal servicemovement of ;the.-slidc plate along a iixed predetermined path for the purpose to be hereinafter made apparent. The guide bars are adjustable both vertically and horizontally by means of bolts 45 so that a sliding t may be effected between the guide bars and slide plate and the latter may be accurately moved along a designated path because this function is determinative of the accurate placing of pits in the path of the piston as will be brought out more `-in detail hereinafter.; Theislide. plate is provided with a transversely extending-undercut 46 into which there extends a top extremity oi adie holder 41 with the latter retained in operable position by means of hanging guides 48. As viewed particularly in Figure 6 of the drawingsgat least .one of the hanging guides is provided with an aperture 49 and on to the slide plate adjacent'thereto there is secured a casing 50 whichA has projecting therethrough an index pin 5l. This pin has, within the confines of the casing,a shoulder.52which forms an abutment, for airelated extremity of a coil spring .53,

. and since the other end of the spring reacts againstv thecasing the index pin will be urged, at all times, toward the die holder. Extending beyondthe-shoulder the pin forms a finger 54 arrangedto `extendintorthe hanging guide aperture and. thus the die holder is locked against unwarranted. or accidental displacement.. Accordingly, this arrangement lpermits a transverse displacement of the die holder and its related components for they purpose. of inspecting or exposing orrepairing the piston.

Confined .withinthe die holder is. a seat 55 which functions as an accuratelyformedmember..against which a. die cushion .56', also. confined withinthe die holder,..may react or be pressed against; the die cushion beingformed of rubber, rubbercompound. or any yieldable` material as will be clearly understood. Arranged within the.,die.holder is .a self-aligningshoe or die 5l', made self-aligning because it bears directly against the die .cushionand .thus may varysomee what .within theholder as thedie isv urgedtoward the anvil` asa result ofa. downward movement oftheupper ram.. This. self-aligning feature insures a full at bearingv of the die or shoe against. asheet of metalv to clamp the, sheet against'the anvil during a pit .removing opera.- tion and eliminater the possibility of .an edge of the dieor shoe bitingintothe sheet. The die is shouldered as at 58 to accommodate a die retainer. 59 whichis removably secured to the die holder to thereby retainthe die, cushion and seat within. the holder.. It. will be here noted that the die extends-downwardly beyondy the limits of the die retainer so that the .latter will not )come .incontact with the sheet of metal beingworked on.

Spotting means has been incorporated in the machine .to spot ina definite, accurate or sure manner. a.. pit appearing in a sheet of metal. Unless the pit is positioned in true vertical alignment with the .path `of vthe piston it will be ob vious.- that the. ultimate .function for which .this

machineY was originally designed and.invented.

may-.not be .expeditiouslyor .economically carried out. Accordingly, anexempliiied structure whichA carries .out parts ,of one oi the objects of this invention. is characterized by a light projector unit 6!! .mounted on the sameendl of the slide plate. as carries the index assembly and disposed toone side, in .an outward direction, of .the vertical limits ,of .the die and. anvil. The projector. unit..ccmprises alight `source unit E 2 .having ex-` tending therefrom a hood 63 leading into a projecting device 64. Forming a part of theY projector unit and spaced away from but in light ray alignment with the projecting device is a reiiector 65 disposed at an angle and arranged to reect a beam of light vertically. As previously indicated the slide plate is designed and carried so that it and its components may be moved from illustrated position inwardly or longitudinally of the machine for a predetermined distance. This distance is calculated'to such a degree that when the slide bar is moved inwardly for the full extent of its permitted travel a beam of light coming from the reflector is concentrated on the piston or anvil chamber. Thus when the slide plate is moved fully inwardly of the machine and the light source is turned on a beam of light is concentrated on the piston or anvil chamber. At this time a sheet of metal is placed on the anvil with a pit appearingy in the sheet properly positioned so that the beam of light will be focused on the pit. The sheet of metal is then held in this position and the slide plate is then returned to its normal or illustrated position at which time the two rams are activated so that the die or shoe will clamp or press the sheet of metal to or against the anvil and the piston will be urged upwardly against what might be termed the underside of the sheet to remove the pit appearing in the top side of the sheet of metal.

Means has been incorporated in the machine for moving the slide plate longitudinally of the machine or from one location to another for the purpose already recited. Toward the accomplishment of the above the upper jaw of the frame has a subjacent cylinder bracket G5 secured thereto. At one end of the cylinder brackets there is suitably mounted a double acting hydraulic cylinder 6l having projecting therefrom in a direction of the slide plate a piston rod S8 arranged to reciprocate through the action of or in response to huid pressure supplied to the hydraulic cylinder by the feed lines S9; the latter of which it may be generally stated, derive their iluid under pressure from the same source that feeds the upper and lower rams: namely a pump and motor assembly indicated in Figure l only of the drawings by the reference character 1E. The travel of the piston rod is arranged to equal the predetermined or required movement of the slide plate so that the ray of reflected light will be concentrated on the anvil chamber or piston when the slide plate is at its innermost location and the die is directly over the anvil when the slide plate is at its outermost location.

Forming a part of the cylnder bracket is a guide block 'il in which there is positioned a movable crosshead 'I2 coupled with the free or outer extremity oi the cylinder rod to be moved as a unit therewith. Connecting the crosshead to the slide plate is a lever arm or link 13 which has one end thereof pivotally secured to the crosshead by a pin 'i4 and another end thereof pivotally attached to the slide plate by a pin '55. Accordingly any action of the hydraulic cylinder rod will be reiectezd in the slide plate. In actual practice the total movement or stroke of the upper ram is less than one-quarter of an inch to effect a clamping action by the die so that no additional provisions need be made in the horizontal slide plate-link-crosshead connection to compensate for the vertical upper ram movement.

Automatic means has been built into the machine for controlling the source of electrical shown) energy for the light source unit 52 so that the light will be turned on when the projector unit is over the anvil and turned oii When the unit is spaced horizontally from the anvil. Toward the accomplishment of the above the guide block has mounted thereon switch means T5 arranged to remain stationary relative to the frame and connected to a source of electrical energy (not This switch means is connected to the light unit 62 so that upon one tripping of the switch means the light unit will be energized and upon another tripping the light unit will be deenergized. Secured to the guide plate is an L- shaped switch bracket Tl having an arm 'I8 thereof projecting inwardly of the machine to Ward the guide block to overlie, in spaced relation, the switch means. The bracket arm is provided with longitudinally spaced webs 'i9 carrying adjustable bolts and 88a which are in horizontal alignment with one another and withy tripping buttons 8! of the switch means therebetween.. When the slide plate is in the position illustrated, that places the die above the anvil, and bolt 8E! has then contacted its related tripping button and the electrical energy is cut off from the light unit. When the slide plate is moved in a different or opposite direction to position the reector plate directly over the piston or anvil chamber, the bolt 82a has contacted its related tripping button to supply electrical energy to the light unit. Thus the source of light is turned on or off as required for the successful operation of the machine.

From the above it will be noted that various changes and alterations may be made to the illustrated and described constructionr without departing from the spirit oi this invention or scope of the appended claims.

I claim:

l. A machine for removing a pit and the like from a metal sheet, said machine comp-rising a member for supporting said metal sheet and having associated therewith an elastic means for engaging one side of said metal sheet, another member spaced from said first named member,

said last named member being horizontally movably mounted on said machine and carrying a from a metal sheet, said machine comprising a member having associated therewith an elastic means for engaging one side of said metal sheet for applying pressure to said sheet at an area directly opposed to said pit, another member spaced from and arranged to move toward said lirst named member for clamping sheet between said members, said second named member 'being arranged to be moved horizontally and comprising a light and shoe, said' light in one location being arranged to focus'k on an area directly over said elastic means for. locating a pit, and said shoe in one location being arranged to bear upon said sheet including said pit.

3. A machine for removing a pit and the like from a metal sheet, said machine comprising a member, elastic means arranged to be forced out of said member for engaging one side of `said metal sheet for applying pressure to said sheet at an area directly opposed to said pit, another member movable toward said first named member, said secondinamed member beingl'movable transversely relative to first named 'member andzcomprising a light adapted to directa. beam toward said elastic means to spot said pit, anda .shoe carried by said second named member and adapted to be pressed against another side of said sheet at an .area including said pit.

4. A machine for removing. a pit and the like from a metal sheet, said machine comprisingra member, elastic means arranged to be forced 'out of said. member for engaging one side of said metal sheet for applying pressure to said sheet at an area directly opposed to said pit, another member movable toward said rst named member, said second named member 'being' movable transversely relative to saidfirst named member and comprising a light adapted to direct a beam toward said elastic means to spot said pit,` a shoe carried by said second named member and adapted to be pressed against another side of said sheet at an area including said pit, switch means for controlling said light, and means carried by said second named member arranged to operate said switch means.

5. A machine for removing a pit and the like from a metal sheet, said machine comprising an anvil having associated therewith an elastic means arranged to be urged therethrough for engaging one side of said metal sheet for applying pressure to said sheet at an area directly opposed to said pit, a slide plate spaced from and arranged to be moved toward said anvil, means for moving said slide pla-te' transversely of said anvil, a light carried by said slide plate and arranged to have a beam therefrom focused on said elastic means for locating said pit directly in line with said elastic means, and a shoe carried by said slide plate arranged to `be moved s0 as to bear against said plate at an area including said pit.

6. A machine for removing a pit and the like from a metal sheet, said machine comprising an anvil having associated therewith an elastic means arranged to be urged therethrough for engaging one side oi said metal sheet for applying pressure to said sheet at an area directly opposed to said pit, a slide plate spaced from and arranged to be moved toward said anvil, means for moving said slide plate transversely of said anvil, a light carried by said slide plate and arranged to have a beam therefrom focused on said elastic means for locating said pit directly in line with said elastic means, ashoe carried by said slide plate arranged to be moved so as to bear `against said plate at an area including said pit, switch means for controlling said light, and means carried by said slide plate for operating said switch means.

7. A machine for removing a pit and the like from a metal sheet, said machine comprising an anvil having associated therewith an elastic means arranged to be urged therethrough for Pfl 8,. engaging-one` side: of said metalsh'eet forxapply' ing pressure to said sheet at an area directly opposed to said pit, a slide plate spaced fromfan'd arranged to be moved toward said anvil,.means pin-connected to said slide plate for moving the latter transversely of said anvil, a light source carried by said slide plate and arranged to'have a beam reflected on said elastic means for locating said pit directly in line with said elastic means, and a shoe carriedv by said slide'plate arranged to be moved so as to bear against said plate at an area including said pit.

8. A machine for' removing a pit and theflike from a metal sheet, said machine Acomprising an anvil having associated therewith an elastic means arranged to be urged therethroughfor engaging one side of said metal sheet for apply.- ing pressure to said sheet at an area directlyop` posed to said pit, horizontally and: vertically movable means spaced from said anvil, means for moving said movable means vertically toward and away from said anvil, means for moving said movable means parallel to said anvil, said movable means comprising a light source arranged to direct a beam reflected on said elastic means -for locating said pit directly in line with said elastic means, and resiliently backed shoe means carried by said movable means and arranged to be pressed against said sheet at an area including said pit.

9. A machine for removing a pit andthe like from a metal sheet, said machine comprising an anvil having associated therewith an elastic means arranged to be urged therethrough for engaging one side of said metal sheet for applying pressure to said sheet at an area directly opposed to said pit, horizontally and vertically movable means spaced from said anvil, means for moving said movable means toward and away from said anvil, a light reiector carried by said movable means, a light carried by said movable means and directed against said reiiector to spot a pit directly in line with said elastic means, a resiliently backed shoe carried .by said movable means and arranged to be pressed against said sheet at an area including said pit, switch means remote from said movable means for controlling.

saidlight, andmeans carried by said. movable means arrangedto control said switch means. DAVID E. MULHOLLAND.

REFERENCES CITED rihe following references are of record lin the iileof this patent:

UNITED STATES PATENTS 

